This is a remix of Mcknights "Prusa i3 circular fan with inductive sensor support"-Holder. It's just the mount. I needed the sensor mount for a 18mm sensor and also wanted a little more stability.
This is just the mount, get the circular duct from there: https://www.thingiverse.com/thing:1272420
It's my first modeling attempt, so it kinda looks like Frankenstein :)